Continuous press for laminating materials



United States atent [72] Inventor Robert A. Caughey Antrim, NewHampshire [21] Appl. No. 741,755

[22] Filed July 1, 1968 [45] Patented Dec. 8, 1970 [73] AssigneeWeyerhaeuser Company Tacoma, Wash.

a corporation of Washington [54] CONTINUOUS PRESS FOR LAMINATING PrimaryExaminer-Edward L. Roberts Attorneys-Leslie G. Noller, John M. Crawfordand Kenneth W. Vernon ABSTRACT: An improved continuous press for themanufacture of laminated wood materials and other wood products whichhas a lower platen consisting of a number of contiguous, unconnectedrigid members and an upper platen parallel to but spaced from the lowerplaten consisting of an endless belt driven solely by transmission offorce to it from the lower platens through the material fed between thetwo platens. The upper surface of the upper platen is in sliding contactwith a series of keyed-together plates, each of the keyed-togetherplates having separate hydraulic rams acting downwardly on each plate tofurnish the required pressure necessary to laminate or consolidate thematerials fed into the press. The

lower, unconnected platen members are driven by a series ofhydraulically operated driving pinions located along each side of thepress and engageable with gear racks on the underside of the unconnectedplaten membens. The driving pinions are spaced a distance apart lessthan the length of the individual, unconnected platen members. Theunconnected platen members are returned from the outfeed end of theconveyor to the infeed end by means of a hydraulically operated elevatorwhich lowers each of the plates at the outfeed end onto a conveyingchain running in a direction opposite the travel of the press. Theconveying chain returns the platen member to the infeed end where it israised into operating position. A hydraulically operated crowderadvances it into contact with the first set of driving pinions whichadvance it into the press. Switches or other sensing devices are used tocoordinate operation of the elevating and crowding mechanisms.

PATENTED DEC 8 I970 sum 2 BF 3 MJM PATENTED DEC 8 I976 SHEET 3 [IF 3owns BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates to a continuous press for laminating wood and woodproducts, and consolidating wood fibrous materials.

2. Prior Art Relating to the Disclosure Presses have been developed forthe continuous laminating of wood and wood products. For example, seeUS. Pat. Nos. 2,729,584; 2,919,732; 2,988,120; and 3,036,967.Development of a press suited for continuous efficient operation and lowmaintenance, however, has remained a problem.

A continuous press for the manufacture of wood particles bonded togetherby thermosetting resins (particleboard) is disclosed in US. Pat. No.3,044,111. This press comprises a stationary lower platen and an upperplaten defining a passage for the material therebetween. Over the lowerplaten is located a series of contiguous, unconnected plates in slidingrelation with the lower platen, the plates driven by a single hydraulicram at the infeed end of the press. Over the upper platen is trained acontinuous belt in sliding contact with the upper platen, the beltdriven through the press solely by frictional engagement of the beltwith the material in contact with the lower platen members being driventhrough the press. The

press described has inherent limitations as to size and pressure whenused in the lamination of wood and wood products. For example, themethod described in the above-mentioned patent for advancing thecontiguous, unconnected platen members through the press by means of asingle hydraulic ram is unsuited to commercial production because of theheavy stresses imposed on the means to advance the plates through thepress, particularly when high pressures are used.

SUMMARY OF THE INVENTION This invention relates to an improved press ofthe type described in U.S. Pat. No. 3,044,1 1 1. In general, theimproved press of this invention comprises a series of contiguous,unconnected rigid platen members resting on a rigid supporting bearingsurface, the platen members forming a lower platen for the press, and anupper platen disposed above the lower platen and substantially parallelthereto, the upper platen consisting of a continuous, movable beltsliding directly on a lubricated, low friction surface. The low frictionsurface consists of a series of short plates keyed together with eachplate having a separate hydraulic rain acting downwardly thereon so asto provide requisite pressure necessary for laminating materialstogether. The lower, unconnected platens are driven through the press bya plurality of power means spaced adjacent each of the lower platenmembers and engageable therewith, each of the power means spaced adistance less than the length of the individual unconnected platenmembers. The power means generally comprises a series of hydraulicallyoperated motors which drive driving pinions located on each side of thepress, the pinions engageable with gear racks located on the undersurface of the contiguous, unconnected, rigid platen members. By using'a multidrive system, the total force required for advancing the lowerplaten members through the press is distributed equally among thedriving pinions, avoiding overloading of the pinions and alleviatingsevere operational problems.

The contiguous, unconnected, lower platen members are returned from theoutfeed end of the press to the infeed end by the combination of ahydraulically operated mechanism which lowers the individual platens outof contact with the material being fed through the press as an exit fromthe outfeed end of the press onto a conveyor chain which moves themembers to the infeed end of the press. At the infeed end a similarhydraulically operated elevating means lifts the platen members to itsnormal operating position in contact with the material being pressed. Ahydraulically operated crowding means located at the infeed end of thepress and at the same level as the platens being driven through thepress engages the raised platen member and advances it into abuttingrelationship with the preceeding platen and subsequently into engagementwith the first set of driving pinions of the multidrive system formovement through the press. Sensing means comprising switches, photocells, or other means are used to coordinate lowering, raising andcrowding of the unconnected platen members in conjunction with operationof the press.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a side elevation of theentry or infeed end of the improved press with parts broken away forbetter illustration.

FIG. 1B is a side elevation of the exit or outfeed end of the improvedpress.

FIG. 2 is a view along section line 2-2 of FIG. 1A.

FIG. 3 is a view along section line 33 of FIG. IA.

FIG. 4 is a view along section line 4-4 of FIG. 1B.

DETAILED DESCRIPTION OF THE DRAWINGS The various parts of the machineare shown in FIGS. 1A and 1B and are mounted on a frame consisting of apair of side members 1 and 2. Each of the side members comprises a lowerportion and an upper portion, the two connected together by stress rods3 which are adjustable. A bearing member 4 is permanently fixed betweenside panels I and 2 in any convenient manner. The top surface of member4 is preferably highly polished to reduce friction. Resting on bearingmember 4 and in sliding contact therewith are a series of rectangular,contiguous, unconnected platens 5 which form the lower platen of thepress. These platens travelthrough the press from the infeed end to theexit end thereof in contiguous, unconnected relation and slide freelybetween members 1 and 2 and on bearing member 4.

The series of platens 5 are moved through the press by pairs ofindividually hydraulically driven driving pinions 6 located on each sideof the press and preferably spaced at distance apart less than thelength of the individual unconnected platens 5. Driving pinions 6 engagegear racks 7 located on the undersurface of each of the platens 5. Asuitable power source such as individual hydraulic motors 8 areconnected to each of the driving pinions 6 by means of sprockets 9 and10 connected together by chains 11. Drive shafts l2 connect each of thehydraulic motor pairs located on each side of the press in order tosynchronize their operation. The platens 5 can be,

moved through the press equally as well by other means. For example, thepinions 6 can be on a common Although the although the drawings indicatedriving pinions extending the full length of the press, there is usuallyno need to extend them to the discharge end. The spacing of the motorsand driving pinions is a function of platen loading which, at thedischarge end of the press, is not significant.

This multipoint drive system distributes the total force required foradvancing the series of platens 5 through the press equally among thedriving pinions so that no pinion is overloaded. Without the multipledrive system severe limitations would be placed on the press withrespect to maximum size and pressure. For example, assuming a press 12%wide and 24 long, a pressure on the workpiece of 200 p.s.i., and anoverall coefficient of friction on 0.1, the total driving force requiredfor forcing the series of platens therethrough would be approximately72,000 lbs. A two pinion drive would, of necessity, have to pullapproximately 36,000 lbs., necessitating special large gears, shafts andmotors. In the improved press of this invention the total load isshared. Using the same example, if 24 2-inch diameter gears are used,each pinion would be torqued to 3,000 pound inches which is well withinlimit of standard gears and motors.

The upper platen 13 consists of a continuous, steel belt or belt ofother suitable metal. The upper belt serves only as a continuous bearingand is moved by the product being pressed. It is not under severetension, and guiding and band tracking problems are substantiallyreduced. The band is trained around a circular surface 14 at the exitend of the press and follows along the top of the press 15 and 16 inreturning to the infeed end. Pressure is exerted on belt or upper platen13 by a series of short plates 17 keyed together at 18. A series ofhydraulic rams 19 connected to the supporting frame have their pistonsattached to each individual plate 17. Plates 17 are in sliding contactwith belt 13. A suitable lubricant may be injected by injecting means17', shown schematically in FIG. 3, between belt 13 and plates 17 tominimize friction therebetween. By having separate, thoughinterconnected, upper pressure plates, a pressure profile through thepress is possible, allowing optimum pressure conditions for theparticular product desired. For example, the press can be operated so asto have a high initial pressure followed by decreasing pressure; agradually increasing, then decreasing pressure; or a graduallyincreasing pressure. This pressure flexibility enables manufacture ofspecialty products where closely controlled conditions are needed.

The individual, unconnected platens 5, when they reach the exit end ofthe press, are returned to the infeed end by an improved conveyingmechanism which lowers the individual platens at the outfeed end of thepress, conveys them to the infeed end of the press, raises them tooperating height and in line with a hydraulic crowder which crowds theplaten into contact with the next adjacent platen and into drivingengagement with the first set of driving pinions at the infeed end ofthe press. The mechanism to lower each of the unconnected platens at theoutfeed end of the press comprises a hydraulically operated table 20which, in raised position, is in line with the path of platens 5 throughthe press. A hydraulic cylinder 21 operates table 20. A control device20 is positioned so as to actuate lowering of table 20 when one of theplatens 5 is resting thereon. Hydraulic cylinder 21 lowers table 20 andthe platen plate 5 to the level of conveyor chains 22 trained aroundsprockets 23. The return conveyor may have a nylon bearing surface sothat platens 5 are not damaged during their conveyance from the outfeedto the infeed end of the conveyor. When one of the platens 5 reaches theinfeed end of the press another hydraulic cylinder 24 attached to table25 is actuated by a suitable control device 24. When platen 5 ispositioned over table 25, the table raises the platen 5 in the path ofcrowder member 26 and in position for entry into the press. Crowdermember 26 is attached to another hydraulic cylinder 27 which is actuatedby control device 27 as soon as platen 5 is raised to the properposition. The crowder member advances platen 5 into engagement with thefirst set of driving pinions 6 at the infeed end of the press and intocontiguous relationship with the next adjacent platen 5. The operationof cylinders 21,24, and 27 is synchronized by suitable control devices21,24' and 27' so that the lowering, raising, and crowding functions areperformed in relation to overall operation of the press.

In operation sheets of wood veneer 28 or other material are fed into theinfeed end of the press. In the case of wood veneer, it is usuallypreheated and coated with a suitable thermosetting adhesive for bondingthe wood laminae together. The laminae are then brought into contact asthey approach the nip end of the press. The length and width of thepress can be adjusted to suit purposes desired. As the laminae enter thepress they are compressed to such a degree that the internal frictionbetween the laminae greatly exceeds the friction between belt 13 andplates 17 and also the friction between the laminae and belt 13. Thispermits the transmission from the moving series of platens 5 to the belt13 of a force sufficient to advance belt 13 through the press.

Many laminated products can be made using the improved press of thisinvention. Wood products overlayed with plastic or fibrous materialmixed with suitable thermosetting resins can also be laminated.

Iclaim:

I. An improved press for manufacturing composite or laminated woodmaterials comprising:

a supporting frame having thereon a substantially horizontal, rigid,supporting bearing surface;

a plur ity of contiguous, unconnected, rigid platen members forming acontinuous lower platen resting on said bearing surface and movable froman infeed end to an outfeed end;

a continuous, movable belt having an undersurface disposed in spacedrelation to the lower platen and defining a passageway, the belt adaptedto be driven solely by forces transmitted to it from the lower platenthrough the material as it is fed between the lower platen and belt;

pressure means operable directly against the upper surface of the lower'run of the belt and in a downward direction toward the lower platen;and

means for driving the lower, unconnected platen members comprising aplurality of power means spaced adjacent the platen members andengageable therewith individually to distribute the driving load alongthe path of said platen members.

2. Apparatus according to claim 1 wherein each of the unconnected, rigidplaten members has gear racks located on its undersurface and whereinthe power means comprises a series of driving pinions engageable withthe gear racks on the unconnected, rigid platen members.

3. Apparatus according to claim 1 wherein the power means are spaced adistance apart less than the length of the individual, unconnectedplaten members.

4. Apparatus according to claim 2 wherein the driving pinions arehydraulically operated.

5. Apparatus according to claim 1 wherein the pressure means includes aplurality of separate plates in slidable contact with the belt and aplurality of hydraulic rams acting downwardly on each plate.

6. Apparatus according to claim 5 wherein the plates linked together.

7. Apparatus according to claim 5 including means for injecting alubricant between the plates in a slidable contact with the belt and thebelt.

8. An improved press for manufacturing composite or laminated woodmaterials comprising:

a supporting frame having thereon a substantially horizontal, rigidsupporting bearing surface;

a plurality of contiguous, unconnecting, rigid platen members forming acontinuous lower platen on said bearing surface and movable from aninfeed end to an outfeed end;

a continuous, movable belt having an undersurface disposed in spacedrelation to the lower platen and adapted to be driven by the forcetransmitted to it from the lower platen through the material fed betweenthe lower platen and upper belt;

pressure means operable against the upper surface of the lower run ofthe belt and in a downward direction toward the lower platen;

means for driving the individual lower platen members; and

means for returning the unconnected platen members from the outfeed endof the press to the infeed end comprising:

a. lowering means to individually and separately lower each of theunconnected members out of contact with the material fed into the pressat the outfeed end thereof;

b. conveying means to convey the platen members from the outfeed end tothe infeed end of the press;

c. elevating means to individually and separately elevate each of theunconnected platen members to its operating position in contact with thematerial being pressed,

d. crowding means located at the infeed end of the press and in linewith the platen member to push the member into engagement with the firstset of driving pinions at the infeed end of the press and intocontiguous relations with the next adjacent platen member; and

e. sensing means for synchronizing lowering, raising and crowding of theplaten members in coordination with operation of the press.

are

zg g UNITED STATES PATENT OFFICE 4 CERTIFICATE OF CORRECTION Patent No.3,545,370 Dated December 8, 1970 Inventor(s) ROBERT A. CAUGHEY It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In column 2, line 48, "common Although the" should read --commonshaft.--;

in column 2, line 49, "although" should read -Although--.

Signed and sealed this 11th day of May". 1971.

(SEAL) Attest:

EBMRDMJLETQPIERQ R. WILLIAM E. SCHUYLER, JR. Attest g Off cerCommissioner of Patents

